I just put a double Nervar crankset this kind on a 1975 Moto Grand Jubile. And when I spin the cranks I swear I hear a sound like something is rubbing somewhere. Only thing I can think of is the bolts on the back of the crankset possible rubbing somewhere on the fixed cup… Is this even possible? The bolts (nuts?) in question


they do get extremely close to the edges of the fixed cup.

Let’s say it’s rubbing ever so slightly, that’s a no go, right? I searched and couldn’t find this question so thought I’d ask.

tia!
Erin

Your new crank probably slides farther in on the spindle than the old one. You can get a different crank or a longer spindle.

Can you slide a piece of paper in there and then rotate to see for sure?

that’s a good idea, I’ll do that now

So I did this and couldn’t really tell much … But, while I was messing around with it I noticed there was some play in the bottom bracket. No idea how that was possible because I checked it before and after I put the cranks on … so anywho, took the nds crank arm off, tightened the bb, put the nds crank arm back on and now there is no sound of rubbing anymore on the drive side!

The sound was coming from inside??? Still confused but at least it’s fixed?

Hopefully the bearings are in the right way around. I somehow managed to fit a headset bearing upside down a while back, and couldn't figure out why it wasn't working. It was a while before the penny dropped; I replaced the now-mangled ball cage with loose balls.

I’m actually using loose bearings but yeah, I’ve made that mistake before with the cages 😅 For some reason it took me a really long time to understand how the cup/cone works but once I understood it I at least know which way I’m supposed to put the cages. I still sometimes mess it up though

the rubbing sound was probably the spindle rubbing the cup/s outer bores....

What type of crank did the new Nervar replace and what brand/length spindle are you using?